From 03bb5147da083cb91e5c8c2599fcb2f8fd05cb8f Mon Sep 17 00:00:00 2001 From: "Derek J. Clark" Date: Sun, 10 May 2026 04:25:39 +0000 Subject: [PATCH] platform/x86: lenovo-wmi-other: Limit adding attributes to supported devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Adds lwmi_is_attr_01_supported, and only creates the attribute subfolder if the attribute is supported by the hardware. Due to some poorly implemented BIOS this is a multi-step sequence of events. This is because: - Some BIOS support getting the capability data from custom mode (0xff), while others only support it in no-mode (0x00). - Some BIOS support get/set for the current value from custom mode (0xff), while others only support it in no-mode (0x00). - Some BIOS report capability data for a method that is not fully implemented. - Some BIOS have methods fully implemented, but no complimentary capability data. To ensure we only expose fully implemented methods with corresponding capability data, we check each outcome before reporting that an attribute can be supported. Checking for lwmi_is_attr_01_supported during remove is not done to ensure that we don't attempt to call cd01 or send WMI events if one of the interfaces being removed was the cause of the driver unloading. Fixes: edc4b183b794 ("platform/x86: Add Lenovo Other Mode WMI Driver") Reported-by: Kurt Borja Closes: https://lore.kernel.org/platform-driver-x86/DG60P3SHXR8H.3NSEHMZ6J7XRC@gmail.com/ Cc: stable@vger.kernel.org Reviewed-by: Rong Zhang Tested-by: Rong Zhang Reviewed-by: Mark Pearson Signed-off-by: Derek J. Clark Link: https://patch.msgid.link/20260510042546.436874-10-derekjohn.clark@gmail.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- drivers/platform/x86/lenovo/wmi-other.c | 92 +++++++++++++++++++++++-- 1 file changed, 88 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/lenovo/wmi-other.c b/drivers/platform/x86/lenovo/wmi-other.c index a06b188eadac..d318ba432fdc 100644 --- a/drivers/platform/x86/lenovo/wmi-other.c +++ b/drivers/platform/x86/lenovo/wmi-other.c @@ -544,6 +544,8 @@ struct tunable_attr_01 { u8 feature_id; u8 device_id; u8 type_id; + u8 cd_mode_id; /* mode arg for searching capdata */ + u8 cv_mode_id; /* mode arg for set/get current_value */ }; /** @@ -625,7 +627,7 @@ static ssize_t attr_capdata01_show(struct kobject *kobj, u32 attribute_id; int value, ret; - attribute_id = tunable_attr_01_id(tunable_attr, LWMI_GZ_THERMAL_MODE_CUSTOM); + attribute_id = tunable_attr_01_id(tunable_attr, tunable_attr->cd_mode_id); ret = lwmi_cd01_get_data(priv->cd01_list, attribute_id, &capdata); if (ret) @@ -690,7 +692,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj, if (mode != LWMI_GZ_THERMAL_MODE_CUSTOM) return -EBUSY; - args.arg0 = tunable_attr_01_id(tunable_attr, mode); + args.arg0 = tunable_attr_01_id(tunable_attr, tunable_attr->cd_mode_id); ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata); if (ret) @@ -703,6 +705,7 @@ static ssize_t attr_current_value_store(struct kobject *kobj, if (value < capdata.min_value || value > capdata.max_value) return -EINVAL; + args.arg0 = tunable_attr_01_id(tunable_attr, tunable_attr->cv_mode_id); args.arg1 = value; ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_SET, @@ -743,6 +746,10 @@ static ssize_t attr_current_value_show(struct kobject *kobj, if (ret) return ret; + /* If "no-mode" is the supported mode, ensure we never send current mode */ + if (tunable_attr->cv_mode_id == LWMI_GZ_THERMAL_MODE_NONE) + mode = tunable_attr->cv_mode_id; + args.arg0 = tunable_attr_01_id(tunable_attr, mode); ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET, @@ -754,6 +761,81 @@ static ssize_t attr_current_value_show(struct kobject *kobj, return sysfs_emit(buf, "%d\n", retval); } +/** + * lwmi_attr_01_is_supported() - Determine if the given attribute is supported. + * @tunable_attr: The attribute to verify. + * + * For an attribute to be supported it must have a functional get/set method, + * as well as associated capability data stored in the capdata01 table. + * + * First check if the attribute has a corresponding data table under custom mode + * (0xff), then under no mode (0x00). If either of those passes, check if the + * supported field of the capdata struct is > 0. If it is supported, store the + * successful mode in the cd_mode_id field of tunable_attr. + * + * If the attribute capdata shows it is supported, attempt to determine the mode + * for the current value property get/set methods using a similar pattern to the + * capdata table check. If the value returned by either mode is 0 or an error, + * assume that mode is not supported. Otherwise, store the successful mode in the + * cv_mode_id field of tunable_attr. + * + * If any of the above checks fail then the attribute is not fully supported. + * + * Return: true if capdata and set/get modes are found, otherwise false. + */ +static bool lwmi_attr_01_is_supported(struct tunable_attr_01 *tunable_attr) +{ + u8 modes[2] = { LWMI_GZ_THERMAL_MODE_CUSTOM, LWMI_GZ_THERMAL_MODE_NONE }; + struct lwmi_om_priv *priv = dev_get_drvdata(tunable_attr->dev); + struct wmi_method_args_32 args = {}; + bool cd_mode_found = false; + bool cv_mode_found = false; + struct capdata01 capdata; + int retval, ret, i; + + /* Determine tunable_attr->cd_mode_id */ + for (i = 0; i < ARRAY_SIZE(modes); i++) { + args.arg0 = tunable_attr_01_id(tunable_attr, modes[i]); + + ret = lwmi_cd01_get_data(priv->cd01_list, args.arg0, &capdata); + if (ret || !capdata.supported) + continue; + + tunable_attr->cd_mode_id = modes[i]; + cd_mode_found = true; + break; + } + + if (!cd_mode_found) + return cd_mode_found; + + dev_dbg(tunable_attr->dev, + "cd_mode_id: %#010x\n", args.arg0); + + /* Determine tunable_attr->cv_mode_id, returns 1 if supported */ + for (i = 0; i < ARRAY_SIZE(modes); i++) { + args.arg0 = tunable_attr_01_id(tunable_attr, modes[i]); + + ret = lwmi_dev_evaluate_int(priv->wdev, 0x0, LWMI_FEATURE_VALUE_GET, + (u8 *)&args, sizeof(args), + &retval); + if (ret || !retval) + continue; + + tunable_attr->cv_mode_id = modes[i]; + cv_mode_found = true; + break; + } + + if (!cv_mode_found) + return cv_mode_found; + + dev_dbg(tunable_attr->dev, "cv_mode_id: %#010x, attribute support level: %#010x\n", + args.arg0, capdata.supported); + + return capdata.supported > 0; +} + /* Lenovo WMI Other Mode Attribute macros */ #define __LWMI_ATTR_RO(_func, _name) \ { \ @@ -877,12 +959,14 @@ static void lwmi_om_fw_attr_add(struct lwmi_om_priv *priv) } for (i = 0; i < ARRAY_SIZE(cd01_attr_groups) - 1; i++) { + cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev; + if (!lwmi_attr_01_is_supported(cd01_attr_groups[i].tunable_attr)) + continue; + err = sysfs_create_group(&priv->fw_attr_kset->kobj, cd01_attr_groups[i].attr_group); if (err) goto err_remove_groups; - - cd01_attr_groups[i].tunable_attr->dev = &priv->wdev->dev; } return;